Paroxysmal nocturnal hemoglobinuria. Blood. 2014;124:2804-2811. [PMID: 25237200 DOI: 10.1182/blood-2014-02-522128]

Population pharmacokinetic, pharmacodynamic and efficacy modeling of SB12 (proposed eculizumab biosimilar) and reference eculizumab

PURPOSE

To describe, compare similarity of pharmacokinetic (PK), pharmacodynamic (PD) and efficacy of SB12 and reference eculizumab (ECU) and find clinically significant covariate relationships.

METHODS

The PK, PD (terminal complement activity) and efficacy (LDH) data of SB12 and ECU were obtained from 289 subjects from phase I and phase III studies. One- and two-compartment PK models with first-order elimination were evaluated for SB12 and ECU. For PD and efficacy, both direct and indirect models were tested. The impact of covariates on PK, PD and efficacy parameters was assessed. Relationship between PK/PD and PD/efficacy was characterized. This modeling was performed using NONMEM version 7.4 (Icon Development Solutions, Ellicott City, MD, USA).

RESULTS

The two-compartment model adequately described the PK of SB12 and ECU, and the subject's weight was chosen as a clinically significant covariate affecting drugs' clearance and central volume of distribution. Treatment group was not a significant covariate affecting clearance. The direct response model using inhibitory sigmoid Emax and sigmoid Emax relationship well described the PK/PD relationship and PD/efficacy relationship of SB12 and ECU, respectively. Through this modeling, the relationships between PK, PD and efficacy were characterized. There were no differences in PK, PD and efficacy parameters between SB12 and ECU in pooled populations of healthy subjects and paroxysmal nocturnal haemoglobinuria (PNH) patients.

CONCLUSION

The population modeling showed PK, PD and efficacy similarities between SB12 and ECU in pooled population of healthy subjects and PNH patients, supporting the totality of evidence on biosimilarity for SB12.

Patient-reported outcomes and daily activity assessed with a digital wearable device in patients with paroxysmal nocturnal hemoglobinuria treated with ravulizumab: REVEAL, a prospective, observational study

BACKGROUND

Paroxysmal nocturnal hemoglobinuria (PNH) is a rare, chronic blood disorder. Symptoms such as fatigue can have a substantial impact on patients' physical activity levels, sleep, quality of life, and work productivity. Ravulizumab treatment can reduce thrombosis risk, improve survival and quality of life, and reduce fatigue in PNH, but information is limited on how it impacts sleep and physical activity. Here, data on resting heart rate, daily physical activity, and sleep in ravulizumab-treated patients with PNH were passively collected via a digital wearable activity-tracking device and patient-reported outcome (PRO) data were collected via weekly surveys in the same cohort.

METHODS

REVEAL was a 32-week prospective observational cohort study in individuals with PNH receiving ravulizumab in the USA. A wrist-worn Fitbit™ collected data on resting heart rate, daily step count, and sleep duration from eligible patients. Patients also completed the following electronic weekly surveys: Functional Assessment of Chronic Illness Therapy (FACIT) - Fatigue, Patient-Reported Outcomes Measurement Information System (PROMIS) Global Physical Health, PROMIS Global Mental Health, PROMIS Sleep-Related Impairment and Sleep Disturbance, and Work Productivity and Activity Impairment Questionnaire - Specific Health Problem (WPAI-SHP). Data collected from the activity trackers and surveys were compared against US general population values reported in the literature.

RESULTS

Twenty-eight ravulizumab-treated patients were included (median age: 34 years; 54% female). PRO scores were within US general population normative values, including FACIT-Fatigue (40.0), PROMIS Global Physical Health (51.0), Global Mental Health (51.0), Sleep-Related Impairment (50.0), and Sleep Disturbance (49.0). Similarly, mean resting heart rate (67 bpm), daily step count (7476), and sleep duration (7.7 h) were within the range of US general population values. Daily step count was positively correlated with PROMIS Global Physical and Mental Health scores.

CONCLUSIONS

This was the first study to use digital monitoring technology to collect data on physical activity and sleep in patients with PNH. The findings indicate that ravulizumab treatment enables patients with PNH to achieve activity levels (heart rate, sleep duration, step count) and quality of life that are comparable to those of the US general population. A weak positive correlation was identified between patient-reported physical and mental health and daily physical activity levels.

The complement model disease paroxysmal nocturnal hemoglobinuria

We describe initial, current, and future aspects of complement activation and inhibition in the rare hematological disease paroxysmal nocturnal hemoglobinuria (PNH). PNH is a rare but severe hematological disorder characterized by complement-mediated intravascular hemolysis resulting in anemia and severe thrombosis. Insights into the complement-mediated pathophysiology ultimately led to regulatory approval of the first-in-class complement inhibitor, eculizumab, in 2007. This anti-complement C5 therapy resulted in the stabilization of many hematologic parameters and dramatically reduced the often fatal, coagulant-resistant thrombotic events. Despite the remarkable clinical success, a substantial proportion of PNH patients experience suboptimal clinical responses during anti-C5 therapy. We describe the identification and mechanistic dissection of four unexpected processes responsible for such suboptimal clinical responses: (1) pharmacokinetic and (2) pharmacodynamic intravascular breakthrough hemolysis, (3) continuing low-level residual intravascular hemolysis, and (4) extravascular hemolysis. Novel complement therapeutics mainly targeting different complement proteins proximal in the cascade attempt to address these remaining problems. With five approved complement inhibitors in the clinic and many more being evaluated in clinical trials, PNH remains one of the complement diseases with the highest intensity of clinical research. Mechanistically unexpected breakthrough events occur not only with C5 inhibitors but also with proximal pathway inhibitors, which require further mechanistic elaboration.

The efficacy and safety of eculizumab in patients and the role of C5 polymorphisms

Eculizumab is an orphan drug with indications for extremely rare autoimmune disorders. It is primarily prescribed for use in patients with paroxysmal nocturnal hemoglobinuria and atypical hemolytic uremic syndrome; but is also highly effective in the treatment of myasthenia gravis, among others. By binding to the C5 protein in the complement system, eculizumab effectively inhibits cellular hemolysis and autoimmune reactions. Despite this effective treatment, some patients reported no improvement in symptoms. Genetic sequencing revealed three distinct C5 mutations in the non-responders and these polymorphisms appeared to be most prevalent among Japanese, Korean and African populations. Here, we present an overview of the current and potential future applications of eculizumab, as well as the disadvantages of eculizumab treatment in patients with C5 polymorphisms.

Improvements in hematologic markers and decreases in fatigue with pegcetacoplan for patients with paroxysmal nocturnal hemoglobinuria and mild or moderate anemia (hemoglobin ≥10 g/dL) who had received eculizumab or were naive to complement inhibitors

BACKGROUND

Although complement component 5 inhibitors (C5is) eculizumab and ravulizumab improve paroxysmal nocturnal hemoglobinuria (PNH) outcomes, patients may experience persistent anemia. This post hoc analysis investigated whether the complement component 3-targeted therapy pegcetacoplan also improved hematologic outcomes and reduced fatigue in patients with PNH and mild/moderate anemia.

METHODS

Patients with PNH and hemoglobin ≥10.0 g/dL at baseline of PADDOCK (N = 6), PRINCE (N = 8), and PEGASUS (N = 11) were included. Before receiving pegcetacoplan, PADDOCK and PRINCE patients were C5i-naive; PEGASUS patients had hemoglobin <10.5 g/dL despite stably dosed eculizumab. Hemoglobin concentrations, percentages of patients with concentrations ≥12 g/dL, and sex-specific normalization were assessed at baseline and after 16 weeks of pegcetacoplan, as were absolute reticulocyte counts (ARCs) and normalization and fatigue scores and normalization.

RESULTS

From baseline to week 16, mean (SD) hemoglobin concentrations increased in C5i-naive patients (PADDOCK: 10.5 [0.4] to 12.7 [1.1] g/dL; PRINCE: 11.3 [1.0] to 14.0 [1.3] g/dL) and those with suboptimal eculizumab responses (PEGASUS: 10.2 [0.2] to 12.8 [2.6] g/dL). Percentage of patients with hemoglobin ≥12 g/dL increased (PADDOCK: 0 to 60.0% [3 of 5 patients]; PRINCE: 25.0% [2 of 8] to 87.5% [7 of 8]; PEGASUS: 0 to 72.7% [8 of 11]). Sex-specific hemoglobin normalization at week 16 occurred in 40.0% (2 of 5) (PADDOCK), 62.5% (5 of 8) (PRINCE), and 63.6% (7 of 11) (PEGASUS). In all studies, mean ARCs decreased from above normal to normal and ARC normalization increased. Mean Functional Assessment of Chronic Illness Therapy-Fatigue scores improved from below to above or near normal. Two patients had serious adverse events (PEGASUS: post-surgery sepsis, breakthrough hemolysis); breakthrough hemolysis resolved without study discontinuation.

CONCLUSION

Patients with PNH and mild/moderate anemia who were C5i-naive or who had suboptimal hemoglobin concentrations despite eculizumab treatment had improved hematologic outcomes and reduced fatigue after initiating or switching to pegcetacoplan.

TRIAL REGISTRATION

Trial registration numbers: PADDOCK (NCT02588833), PRINCE (NCT04085601; EudraCT, 2018-004220-11), PEGASUS (NCT03500549).

CSMD1 regulates brain complement activity and circuit development

Complement proteins facilitate synaptic elimination during neurodevelopmental pruning, but neural complement regulation is not well understood. CUB and Sushi Multiple Domains 1 (CSMD1) can regulate complement activity in vitro, is expressed in the brain, and is associated with increased schizophrenia risk. Beyond this, little is known about CSMD1 including whether it regulates complement activity in the brain or otherwise plays a role in neurodevelopment. We used biochemical, immunohistochemical, and proteomic techniques to examine the regional, cellular, and subcellular distribution as well as protein interactions of CSMD1 in the brain. To evaluate whether CSMD1 is involved in complement-mediated synapse elimination, we examined Csmd1-knockout mice and CSMD1-knockout human stem cell-derived neurons. We interrogated synapse and circuit development of the mouse visual thalamus, a process that involves complement pathway activity. We also quantified complement deposition on synapses in mouse visual thalamus and on cultured human neurons. Finally, we assessed uptake of synaptosomes by cultured microglia. We found that CSMD1 is present at synapses and interacts with complement proteins in the brain. Mice lacking Csmd1 displayed increased levels of complement component C3, an increased colocalization of C3 with presynaptic terminals, fewer retinogeniculate synapses, and aberrant segregation of eye-specific retinal inputs to the visual thalamus during the critical period of complement-dependent refinement of this circuit. Loss of CSMD1 in vivo enhanced synaptosome engulfment by microglia in vitro, and this effect was dependent on activity of the microglial complement receptor, CR3. Finally, human stem cell-derived neurons lacking CSMD1 were more vulnerable to complement deposition. These data suggest that CSMD1 can function as a regulator of complement-mediated synapse elimination in the brain during development.

CD59 gene: 143 haplotypes of 22,718 nucleotides length by computational phasing in 113 individuals from different ethnicities

BACKGROUND

CD59 deficiency due to rare germline variants in the CD59 gene causes disabilities, ischemic strokes, neuropathy, and hemolysis. CD59 deficiency due to common somatic variants in the PIG-A gene in hematopoietic stem cells causes paroxysmal nocturnal hemoglobinuria. The ISBT database lists one nonsense and three missense germline variants that are associated with the CD59-null phenotype. To analyze the genetic diversity of the CD59 gene, we determined long-range CD59 haplotypes among individuals from different ethnicities.

METHODS

We determined a 22.7 kb genomic fragment of the CD59 gene in 113 individuals using next-generation sequencing (NGS), which covered the whole NM_203330.2 mRNA transcript of 7796 base pairs. Samples came from an FDA reference repository and our Ethiopia study cohorts. The raw genotype data were computationally phased into individual haplotype sequences.

RESULTS

Nucleotide sequencing of the CD59 gene of 226 chromosomes identified 216 positions with single nucleotide variants. Only three haplotypes were observed in homozygous form, which allowed us to assign them unambiguously as experimentally verified CD59 haplotypes. They were also the most frequent haplotypes among both cohorts. An additional 140 haplotypes were imputed computationally.

DISCUSSION

We provided a large set of haplotypes and proposed three verified long-range CD59 reference sequences, based on a population approach, using a generalizable rationale for our choice. Correct long-range haplotypes are useful as template sequences for allele calling in high-throughput NGS and precision medicine approaches, thus enhancing the reliability of clinical diagnostics. Long-range haplotypes can also be used to evaluate the influence of genetic variation on the risk of transfusion reactions or diseases.

Development of a target concentration intervention to individualize paroxysmal nocturnal hemoglobinuria treatment with pegcetacoplan

Pegcetacoplan (Aspaveli®/Empaveli™) is a factor C3 inhibitor that is approved for the treatment of paroxysmal nocturnal hemoglobinuria. An individualized dosing strategy might be useful to improve patient-friendliness and cost-effectiveness of this very expensive drug. Therefore, the aim of this study was to develop an individualized treatment regimen for pegcetacoplan based on the pharmacokinetic-pharmacodynamic data of the manufacturer. We conducted a clinical trial simulation with the approved dosing regimen of 1080 mg twice-weekly and a target concentration intervention-based dosing regimen in patients with and without prior eculizumab use. For eculizumab-naïve patients, the target concentration intervention-based dosing regimen resulted in a comparable fraction of patients with LDH normalization (LDH < 226 U/L) and hemoglobulin normalization (> 12 g/dL) compared to the approved regimen (LDH 50.2% and 50.0% respectively and hemoglobulin 45.6% and 44.4%). A modest dose reduction of ~ 5% was possible with target concentration intervention-based dosing. An intensified dosing interval was necessary in 2.3% of the patients however an interval prolongation was possible in 28.2% of the patients. Similar results were obtained for patients prior treated with eculizumab. In this study we show the potential of an individualized dosing regimen of pegcetacoplan with can improve patient friendliness in approximately 30% of the patients and improve therapy in approximately 2% of the patients at slightly reduced costs.

Consensus recommendations for optimising the diagnosis and treatment of paroxysmal nocturnal haemoglobinuria in Singapore

Introduction

Paroxysmal nocturnal haemoglobinuria (PNH) is a rare haematologic disease characterised by intravascular haemolysis, thrombophilia and bone marrow failure. There is a lack of established clinical guidance on the screening, diagnosis and manage-ment of PNH in Singapore. A relatively low level of awareness among healthcare professionals regarding PNH manifestations further contributes to diagnostic delays. Additionally, limited access to complement inhibitors, like eculizumab, may delay treatment and impact patient outcomes.

Method

Nine haematologists from different institu-tions in Singapore convened to formulate evidence-based consensus recommendations for optimising the diagnosis and management of patients with PNH and improving access to novel treatments. The experts reviewed the existing literature and international guidelines published from January 2010 to July 2023, focusing on 7 clinical questions spanning PNH screening, diagnostic criteria, investigations, treatment and monitoring of subclinical and classic disease, PNH with underlying bone marrow disorders, and PNH in pregnancy. A total of 181 papers were reviewed to formulate the statements. All experts voted on the statements via 2 rounds of Delphi and convened for an expert panel discussion to finetune the recommendations.

Results

Sixteen statements have been formulated for optimising the screening, diagnosis and management of PNH. Upon confirmation of PNH diagnosis, individuals with active haemolysis and/or thrombosis should be considered for anti-complement therapy, with eculizumab being the only approved drug in Singapore.

Conclusion

The current recommendations aim to guide the clinicians in optimising the screening, diagnosis and management of PNH in Singapore.

Pharmacokinetics, pharmacodynamics, efficacy, and safety of ravulizumab in pediatric paroxysmal nocturnal hemoglobinuria

ABSTRACT

Paroxysmal nocturnal hemoglobinuria (PNH) is a rare hematologic disease of uncontrolled terminal complement activation leading to intravascular hemolysis, thrombotic events and increased morbidity and mortality. This phase 3, open-label, single-arm, multicenter study evaluated ravulizumab treatment in eculizumab-naive or -experienced pediatric patients (aged <18 years) with PNH over a 26-week primary evaluation period (PEP) and 4-year extension period (EP). Patients included in the study received weight-based intravenous ravulizumab dosing. Primary end points were pharmacokinetic and pharmacodynamic parameters to confirm complement component 5 (C5) inhibition by ravulizumab; secondary end points assessed the efficacy (including percentage change in lactate dehydrogenase levels over time) and safety of ravulizumab. Thirteen patients, 5 (38.5%) eculizumab-naive and 8 (61.5%) eculizumab-experienced, were enrolled. Ravulizumab Ctrough levels were above the pharmacokinetic threshold of 175 μg/mL in the PEP and EP except in 1 patient. At the end of the study, pre- and post-infusion mean ± standard deviation serum ravulizumab concentrations were 610.50 ± 201.53 μg/mL and 518.29 ± 109.67 μg/mL for eculizumab-naive and eculizumab-experienced patients, respectively. After the first ravulizumab infusion, serum-free C5 concentrations were <0.5 μg/mL in both cohorts until the end of the study (0.061 ± 0.021 μg/mL and 0.061 ± 0.018 μg/mL for eculizumab-naive and eculizumab-experienced patients, respectively). Compared with baseline, ravulizumab improved and maintained efficacy outcomes in both groups. Ravulizumab had an acceptable safety profile with no new safety signals identified, and provided immediate, complete, and sustained terminal complement inhibition, translating to clinical benefit for pediatric patients with PNH. This trial was registered at www.ClinicalTrials.gov as #NCT03406507.

Comparison of human leukocyte antigen in patients with paroxysmal nocturnal hemoglobinuria of different clone sizes

Glycosylphosphatidylinositol-anchored protein-deficient hematopoietic stem and progenitor cell development caused by PIGA mutations cannot fully explain the pathogenesis of paroxysmal nocturnal hemoglobinuria (PNH). Herein, patients newly diagnosed with PNH at our hospital between April 2019 and April 2021 were recruited. The human leukocyte antigen (HLA) class I and II loci were analyzed, and patients were stratified by PNH clone sizes: small (< 50%) and large (≥ 50%). In 40 patients (29 males; 72.5%), the median PNH clone size was 72%. Thirteen (32.5%) and twenty-seven (67.5%) patients harbored small and large PNH clones, respectively. DRB1*15:01 and DQB1*06:02 had higher frequencies in patients with PNH than in healthy controls (adjusted P-value = 4.10 × 10-4 and 4.10 × 10-4, respectively). Whole HLA class I and II allele contributions differed (P = 0.046 and 0.065, not significant difference) when comparing patients with small and large PNH clones. B*13:01 and C*04:01 allelic frequencies were significantly higher in patients with small clones (P = 0.032 and P = 0.032, respectively). Patients with small clones had higher class II HLA evolutionary divergence (HED) (P = 0.041) and global class I and II HED (P = 0.019). In the entire cohort, 17 HLA aberrations were found in 11 (27.5%) patients. No significant differences in HLA aberrations were found between patients with small or large clones. In conclusion, patients with small clones tended to have a higher frequency of immune attack-associated alleles. A higher HED in patients with small clones may reflect a propensity for T cell-mediated autoimmunity. HLA aberrations were similar between patients with small and large clones.

Recent advances in cell membrane camouflaged nanotherapeutics for the treatment of bacterial infection

Infectious diseases caused by bacterial infections are common in clinical practice. Cell membrane coating nanotechnology represents a pioneering approach for the delivery of therapeutic agents without being cleared by the immune system in the meantime. And the mechanism of infection treatment should be divided into two parts: suppression of pathogenic bacteria and suppression of excessive immune response. The membrane-coated nanoparticles exert anti-bacterial function by neutralizing exotoxins and endotoxins, and some other bacterial proteins. Inflammation, the second procedure of bacterial infection, can also be suppressed through targeting the inflamed site, neutralization of toxins, and the suppression of pro-inflammatory cytokines. And platelet membrane can affect the complement process to suppress inflammation. Membrane-coated nanoparticles treat bacterial infections through the combined action of membranes and nanoparticles, and diagnose by imaging, forming a theranostic system. Several strategies have been discovered to enhance the anti-bacterial/anti-inflammatory capability, such as synthesizing the material through electroporation, pretreating with the corresponding pathogen, membrane hybridization, or incorporating with genetic modification, lipid insertion, and click chemistry. Here we aim to provide a comprehensive overview of the current knowledge regarding the application of membrane-coated nanoparticles in preventing bacterial infections as well as addressing existing uncertainties and misconceptions.

Exploring treatment strategies for paroxysmal nocturnal hemoglobinuria: an overview of registered clinical trials

Paroxysmal nocturnal hemoglobinuria (PNH) is a rare, acquired disease in which blood cells lack anchored proteins that regulate the complement system. The erythrocytes are then destroyed because of uncontrolled complement activity, leading to intravascular hemolysis (IVH) and a high risk of thrombosis outcome. A huge alteration in the treatment of the disease was the development of terminal complement inhibitors, with the achievement of IVH blockade, reduction or abolishment of red blood cell (RBC) transfusions, and thromboembolic events prevention. However, patients treated with these inhibitors can still present extravascular hemolysis (EVH) caused by C3 activation and residual IVH or clinically relevant levels of breakthrough hemolysis (BTH). Proximal complement inhibitors turned out to be the key to the solution of this problem by targeting components of the proximal complement pathway, avoiding intra and extravascular hemolysis. FDA approved eculizumab, ravulizumab (terminal inhibitors), pegcetacoplan, iptacopan, and danicopan (proximal inhibitors) as a treatment for PNH so far. Various clinical trials are underway to find the most effective method to treat patients with PNH. This review aimed to summarize 71 registered clinical trials in the ClinicalTrials.gov database with the various treatment drugs, possible mechanisms, and novel findings related to PNH treatment.

Clinical and laboratory profile of patients with positive direct antiglobulin test attended at a university hospital in Goias, Brazil

OBJECTIVE

To clinically and laboratory characterize patients with a positive direct antiglobulin test (DAT) treated at the Hospital das Clínicas of the Federal University of Goiás (HC-UFG).

METHODS

A retrospective, descriptive, cross-sectional study was carried out collecting data from medical records of patients with a positive DAT who were treated at HC-UFG between August 2021 and August 2022.

RESULTS

Eighty-four patients with positive polyspecific DAT results were screened in the clinical laboratory. Fifty-four patients had a laboratory profile compatible with autoimmune hemolytic anemia (AIHA), however, among these, 16 patients already had a diagnosis of AIHA in their medical records. The most common symptoms present among AIHA patients were pallor, asthenia, fatigue and dyspnea. For the remaining patients, the most common symptoms were severe thrombocytopenia, anemia, renal dysfunction, fever, myalgia, headache, thrombosis, asthenia, hematuria and joint pain. Only one patient had primary AIHA, that is, he had no evident underlying disease. The majority of AIHA patients (75 %) underwent corticosteroid therapy with 60 % having a positive response. For patients without AIHA, prednisone was the most frequently prescribed medication in 17 (25 %) patients, followed by hydroxychloroquine (14 patients - 20.1 %).

CONCLUSION

It is essential to evaluate patients with positive DAT in detail in order to understand the real clinical case. The DAT serological result alone does not arrive at a conclusive diagnosis of AIHA, and so it must be evaluated in conjunction with both clinical data and other laboratory tests, such as hemoglobin concentration and hemolysis tests (reticulocytes, lactate dehydrogenase and/or haptoglobin).

Health-related quality of life and influencing factors of patients with paroxysmal nocturnal hemoglobinuria in China

BACKGROUND

Paroxysmal nocturnal hemoglobinuria (PNH) is a rare blood disorder, leading to various complications and impairments in patients' health-related quality of life (HRQOL). Limited research has been conducted to evaluate the HRQOL of Chinese patients with PNH. Understanding the HRQOL in this specific population is crucial for providing effective healthcare interventions and improving patient' health outcomes. This study aimed to assess HRQOL of Chinese patients with PNH, and identify key determinants.

METHODS

A cross-sectional study was conducted during 2022 to recruit patients with PNH in China. The study population was recruited from PNH China, one of the largest public welfare PNH patient mutual aid organization in China. Data were collected via an online questionnaire including the EQ-5D-5L (5L), and social-demographic and clinical characteristics. Descriptive statistics were employed to summarize the characteristics of the participants and their HRQOL. Multiple linear and logistic regression analyses were adopted to explore key factors affecting HRQOL.

RESULTS

A total of 329 valid questionnaires were collected. The mean (SD) age of the patients was 35.3 (10.0) years, with 52.3% of them being male. The patients reported more problems in Anxiety/Depression (81.5%) and Pain/Discomfort (69.9%) dimensions compared to the other three 5L dimensions. The mean (SD) of 5L health utility score (HUS) and EQ-VAS score were 0.76 (0.21) and 62.61 (19.20), respectively. According to multiple linear regression, initial symptoms (i.e., Anemia [fatigue, tachycardia, shortness of breath, headache] and back pain) and complication of thrombosis were significant influencing factors affecting 5L HUS. Total personal income of the past year, initial symptom of hemoglobinuria and complication of thrombosis were significantly influencing factors of VAS score. Social-demographic and clinical characteristics, such as gender, income, and thrombosis, were also found to be significantly related to certain 5L health problems as well.

CONCLUSION

Our study manifested the HRQOL of PNH patients in China was markedly compromised, especially in two mental-health related dimensions, and revealed several socio-demographic and clinical factors of their HRQOL. These findings could be used as empirical evidence for enhancing the HRQOL of PNH patients in China.

A year in pharmacology: new drugs approved by the US Food and Drug Administration in 2023

With 54 new drugs and seven cellular and gene therapy products, the approvals by the US Food and Drug Administration (FDA) recovered 2023 from the 2022 dent back to the levels of 2020-2021. As in previous years of this annual review, we assign these new drugs to one of three levels of innovation: first drug against a condition ("first-in-indication"), first drug using a novel molecular mechanism ("first-in-class"), and "next-in-class," i.e., a drug using an already exploited molecular mechanism. We identify four (7%) "first-in-indication," 22 (36%) "first-in-class," and 35 (57%) "next-in-class" drugs. By treatment area, rare diseases (54%) and cancer drugs (23%) were once again the most prevalent (and partly overlapping) therapeutic areas. Other continuing trends were the use of accelerated regulatory approval pathways and the reliance on biopharmaceuticals (biologics). 2023 marks the approval of a first therapy based on CRISPR/Cas9 gene editing.

Eculizumab for paroxysmal nocturnal hemoglobinuria: Two cases of successful pregnancy outcomes

Paroxysmal nocturnal hemoglobinuria is a rare disease with the incidence ranging from 0.08 to 0.57 per 100,000 person-years. Up to 25% of cases in women are detected during pregnancy. We report two cases of successful pregnancy outcomes in patients treated with eculizumab, pointing out the importance of interdisciplinary approach in these high-risk pregnancies.

Safety and Efficacy of Pegcetacoplan in Adult Patients with Paroxysmal Nocturnal Hemoglobinuria over 48 Weeks: 307 Open-Label Extension Study

INTRODUCTION

Paroxysmal nocturnal hemoglobinuria (PNH) is a rare, life-threatening disease characterized by complement-mediated hemolysis and thrombosis. Pegcetacoplan, the first targeted complement component 3 (C3) PNH therapy, was safe and efficacious in treatment-naive and pre-treated patients with PNH in five clinical trials.

METHODS

The 307 open-label extension (OLE) study (NCT03531255) is a non-randomized, multicenter extension study of long-term safety and efficacy of pegcetacoplan in adult patients with PNH who completed a pegcetacoplan parent study. All patients received pegcetacoplan. Outcomes at the 48-week data cutoff (week 48 of 307-OLE or August 27, 2021, whichever was earlier) are reported. Hemoglobin concentrations, Functional Assessment of Chronic Illness Therapy (FACIT)-Fatigue scores, and transfusion avoidance were measured. Hemoglobin > 12 g/dL and sex-specific hemoglobin normalization (i.e., male, ≥ 13.6 g/dL; female, ≥ 12 g/dL) were assessed as percentage of patients with data available and no transfusions 60 days before data cutoff. Treatment-emergent adverse events, including hemolysis, were reported.

RESULTS

Data from 137 patients with at least one pegcetacoplan dose at data cutoff were analyzed. Mean (standard deviation [SD]) hemoglobin increased from 8.9 (1.22) g/dL at parent study baseline to 11.6 (2.17) g/dL at 307-OLE entry and 11.6 (1.94) g/dL at data cutoff. At parent study baseline, mean (SD) FACIT-Fatigue score of 34.1 (11.08) was below the general population norm of 43.6; scores improved to 42.8 (8.79) at 307-OLE entry and 42.4 (9.84) at data cutoff. In evaluable patients, hemoglobin > 12 g/dL occurred in 40.2% (43 of 107) and sex-specific hemoglobin normalization occurred in 31.8% (34 of 107) at data cutoff. Transfusion was not required for 114 of 137 patients (83.2%). Hemolysis was reported in 23 patients (16.8%). No thrombotic events or meningococcal infections occurred.

CONCLUSION

Pegcetacoplan sustained long-term improvements in hemoglobin concentrations, fatigue reduction, and transfusion burden. Long-term safety findings corroborate the favorable profile established for pegcetacoplan.

TRIAL REGISTRATION

ClinicalTrials.gov identifier, NCT03531255.

Abnormal expression of CUX1 influences autophagy activation in paroxysmal nocturnal hemoglobinuria

The mechanism underlying autophagy in paroxysmal nocturnal hemoglobinuria (PNH) remains largely unknown. We previously sequenced the entire genome exon of the CD59- cells from 13 patients with PNH and found genes such as CUX1 encoding Cut-like homeobox 1. Peripheral blood samples from 9 patients with PNH and 7 healthy control subjects were obtained to measure CUX1 expression. The correlation between CUX1 messenger RNA expression and PNH clinical indicators was analyzed. To simulate CUX1 expression in patients with PNH, we generated a panel of PNH cell lines by knocking out PIGA in K562 cell lines and transfected lentivirus with CUX1. CCK-8 and EDU assay assessed cell proliferation. Western blotting was used to detect Beclin-1, LC3A, LC3B, ULK1, PI3K, AKT, p-AKT, mTOR, and p-mTOR protein levels. Autophagosomes were observed with transmission electron microscopy. Chloroquine was used to observe CUX1 expression in PNH after autophagy inhibition. Leukocytes from patients with PNH had lower levels of CUX1 messenger RNA expression and protein content than healthy control subjects. The lactose dehydrogenase level and the percentage of PNH clones were negatively correlated with CUX1 relative expression. We reduced CUX1 expression in a PIGA knockout K562 cell line, leading to increased cell proliferation. Levels of autophagy markers Beclin-1, LC3B, LC3A, and ULK1 increased, and autophagosomes increased. Furthermore, PI3K/AKT/mTOR protein phosphorylation levels were lower. CUX1 expression did not change and cell proliferation decreased in CUX1 knocked down PNH cells after inhibition of autophagy by chloroquine. In brief, CUX1 loss-of-function mutation resulted in stronger autophagy in PNH.

Dermatologic manifestations of hematologic disorders

Distinguishing key morphologic features and understanding the pathophysiology of common cutaneous manifestations of hematologic disorders is essential to ensure prompt and appropriate treatment. In fact, classic cutaneous signs may provide the first clue to the diagnosis of an underlying hematologic disease. Disorders of coagulation, vascular abnormalities, or cutaneous infiltration and deposition are responsible for the underlying pathophysiology of cutaneous manifestations in the majority of cases. Hematologists often feel ill-equipped in identifying morphologic changes in the skin. Thus, the purpose of this review is to provide a comprehensive overview of classic cutaneous manifestations and diagnostic considerations of the associated hematologic conditions. Though there is a specific focus on non-malignant disorders, those straddling the spectrum of malignancy are also discussed. In many disease states, the skin may serve as an important marker of an emerging hematologic disorder, so close collaboration and multidisciplinary input remain essential to provide optimal and timely care for these patients.

What is the role of complement in bystander hemolysis? Old concept, new insights

INTRODUCTION

Bystander hemolysis occurs when antigen-negative red blood cells (RBCs) are lysed by the complement system. Many clinical entities including passenger lymphocyte syndrome, hyperhemolysis following blood transfusion, and paroxysmal nocturnal hemoglobinuria are complicated by bystander hemolysis.

AREAS COVERED

The review provides data about the role of the complement system in the pathogenesis of bystander hemolysis. Moreover, future perspectives on the understanding and management of this syndrome are described.

EXPERT OPINION

Complement system can be activated via classical, alternative, and lectin pathways. Classical pathway activation is mediated by antigen-antibody (autoantibodies and alloantibodies against autologous RBCs, infectious agents) complexes. Alternative pathway initiation is triggered by heme, RBC microvesicles, and endothelial injury that is a result of intravascular hemolysis. Thus, C5b is formed, binds with C6-C9 compomers, and MAC (C5b-9) is formulated in bystander RBCs membranes, leading to cell lysis. Intravascular hemolysis, results in activation of the alternative pathway, establishing a vicious cycle between complement activation and bystander hemolysis. C5 inhibitors have been used effectively in patients with hyperhemolysis syndrome and other entities characterized by bystander hemolysis.

Evaluation of the impact of two C5 genetic variants on C5-eculizumab complex stability at the molecular level

Complement C5 is the target of the monoclonal antibody eculizumab, used in complement dysregulating disorders, like the rare disease Paroxysmal Nocturnal Hemoglobinuria (PNH). PNH is an acquired hematopoietic stem cell condition characterized by aberrant destruction of erythrocytes, chronic hemolytic anemia, and thromboembolism propensity. C5 is a protein component of the complement system which is part of the immune system of the body and plays a prominent role in the destruction of red blood cells, misidentifying them as a threat. This work describes the application of molecular dynamics simulations to the study of the underlying interactions between complement C5 and eculizumab. This study also reveals the importance of single nucleotide polymorphisms on C5 protein concerning the effective inhibition of the mAB, involving the mechanistic events taking place at the interface spots of the complex. The predicted conformational change in the C5 Arg885/His/Cys mutation has implications on the protein's interaction with eculizumab, compromising their compatibility. The acquired insights into the conformational changes, dynamics, flexibility, and interactions shed light on the knowledge of the function of this biomolecule providing answers about the poor response to the treatment in PNH patient carriers of the mutations. By investigating the intricate dynamics, significant connections between C5 and eculizumab can be uncovered. Such insights may aid in the creation of novel compounds or lead to the enhancement of eculizumab's efficacy.Communicated by Ramaswamy H. Sarma.

Classic paroxysmal nocturnal haemoglobinuria presenting with intestinal malabsorption syndrome, acute abdomen and acute kidney injury

A male patient in his 30s presented with complaints of acute abdominal pain, black stools and red-coloured urine. CT revealed thrombi in the splenic and left renal veins, leading to infarctions. An endoscopy displayed scalloping of the duodenal folds, indicative of intestinal malabsorption syndrome (IMS). Histopathological examination confirmed IMS. Due to the presence of intravascular haemolysis, haemoglobinuria and thrombotic complications, paroxysmal nocturnal haemoglobinuria (PNH) was suspected and subsequently confirmed by flow cytometry. Thus, a diagnosis of classic PNH with IMS and thrombotic complications was established. This unique case highlights the coexistence of PNH and IMS, resembling the complement hyperactivation, angiopathic thrombosis and protein-losing enteropathy disease, suggesting potential shared pathophysiology.

Impact of Lactate Dehydrogenase and Hemoglobin Levels on Clinical Outcomes in Patients With Paroxysmal Nocturnal Hemoglobinuria: Results From the National Korean PNH Registry

BACKGROUND

Paroxysmal nocturnal hemoglobinuria (PNH) is a rare hematologic disorder caused by uncontrolled terminal complement activation, which leads to intravascular hemolysis (IVH), thromboembolism (TE), renal failure, and premature mortality.

METHODS

We performed a secondary analysis of data collected from patients enrolled in the Korean National PNH Registry to assess the relative importance of risk factors, specifically lactate dehydrogenase (LDH) and hemoglobin (Hb), in predicting the incidence of TE, impaired renal function, and death in complement inhibitor-naïve patients with PNH.

RESULTS

Multivariate regression modeling indicated that LDH ≥ 1.5 × upper limit of normal (ULN), male sex, and pain were associated with increased risk of TE (P = 0.016, 0.045, and 0.033, respectively), hemoglobinuria and pain were associated with an increased risk of impaired renal function (P = 0.034 and 0.022, respectively), and TE was associated with an increased incidence of death (P < 0.001). Hb < 8 g/dL was not a predictor of TE, impaired renal function, or death in multivariate regression analyses. Standardized mortality ratio analysis indicated that LDH ≥ 1.5 × ULN (P < 0.001), Hb < 8 g/dL (P < 0.001), and Hb ≥ 8 g/dL (P = 0.004) were all risk factors for death; in contrast, patients with LDH < 1.5 × ULN had similar mortality to the general population.

CONCLUSION

In complement inhibitor-naïve patients with PNH, LDH ≥ 1.5 × ULN was a significant predictor of TE, and TE was a significant predictor of death. Hb was not a significant predictor of TE, impaired renal function, or death. Therefore, controlling IVH will improve clinical outcomes for patients with PNH.

Paroxysmal nocturnal hemoglobinuria: Review of the patient experience and treatment landscape

Paroxysmal nocturnal hemoglobinuria (PNH) is a rare disorder caused by complement-mediated hemolysis and thrombosis through the alternative pathway. The most common symptom of PNH is fatigue due to chronic anemia, which can negatively impact quality of life (QoL) and affect overall well-being. The currently approved therapies for PNH significantly limit intravascular hemolysis (IVH) and reduce the risk of thrombosis; however, they are associated with an infusion schedule that can become burdensome, and not all patients experience complete disease control. Several new complement inhibitors are in development that address the need for convenient routes of administration and aim to provide better disease control. With the variety of new treatment options on the horizon, hematologic markers as well as QoL concerns, patient opinion, and lifestyle factors should be considered to choose the optimal PNH treatment for each specific patient.

Investigation of Glycosylphosphatidylinositol (GPI)-Plasma Membrane Interaction in Live Cells and the Influence of GPI Glycan Structure on the Interaction

Glycosylphosphatidylinositols (GPIs) need to interact with other components in the cell membrane to transduce transmembrane signals. A bifunctional GPI probe was employed for photoaffinity-based proximity labelling and identification of GPI-interacting proteins in the cell membrane. This probe contained the entire core structure of GPIs and was functionalized with photoreactive diazirine and clickable alkyne to facilitate its crosslinking with proteins and attachment of an affinity tag. It was disclosed that this probe was more selective than our previously reported probe containing only a part structure of the GPI core for cell membrane incorporation and an improved probe for studying GPI-cell membrane interaction. Eighty-eight unique membrane proteins, many of which are related to GPIs/GPI-anchored proteins, were identified utilizing this probe. The proteomics dataset is a valuable resource for further analyses and data mining to find new GPI-related proteins and signalling pathways. A comparison of these results with those of our previous probe provided direct evidence for the profound impact of GPI glycan structure on its interaction with the cell membrane.

Clonal Hematopoiesis, Inflammation, and Hematologic Malignancy

Somatic or acquired mutations are postzygotic genetic variations that can occur within any tissue. These mutations accumulate during aging and have classically been linked to malignant processes. Tremendous advancements over the past years have led to a deeper understanding of the role of somatic mutations in benign and malignant age-related diseases. Here, we review the somatic mutations that accumulate in the blood and their connection to disease states, with a particular focus on inflammatory diseases and myelodysplastic syndrome. We include a definition of clonal hematopoiesis (CH) and an overview of the origins and implications of these mutations. In addition, we emphasize somatic disorders with overlapping inflammation and hematologic disease beyond CH, including paroxysmal nocturnal hemoglobinuria and aplastic anemia, focusing on VEXAS (vacuoles, E1 enzyme, X-linked, autoinflammatory, somatic) syndrome. Finally, we provide a practical view of the implications of somatic mutations in clinical hematology, pathology, and beyond.

COVID-19 vaccination prevents a more severe course and treatment with complement inhibitors reduce worsening hemolysis during the Omicron pandemic in patients with PNH: a single-center study

OBJECTIVE

Paroxysmal nocturnal hemoglobinuria (PNH) is a rare acquired disease characterized by chronic complement-mediated hemolysis. The concentrated outbreak of coronavirus disease 2019 (COVID-19) in China after 6 December 2022, provided an opportunity to observe the disease course of PNH during an active Omicron infection epidemic.

PATIENTS AND METHOD

Patients diagnosed with PNH at Peking Union Medical College Hospital (PUMCH) before 6 December 2022, were followed up until 10 April 2023. Clinical data related to coronavirus infection and hemolysis were recorded. Factors influencing the infection and severity rate of Omicron, as well as hemolysis provocation, were analyzed.

RESULTS

In total, 131 patients with PNH were included in this retrospective analysis; 87.8% were infected with Omicron. Among them, 15.7% met the criteria for severity, and 1 patient died (0.87%). No protective factors were identified against Omicron infections. However, patients with severe Omicron infection (n = 18) had a lower vaccination rate than those with non-severe infection (n = 97; p = 0.015). Among those infected (n = 115) with Omicron, there was a significant increase in lactate dehydrogenase (LDH) levels compared with those in the uninfected group (n = 16, p = 0.000). Patients with severe infections (n = 18) had even higher LDH increase rates than those without severe infections (n = 97; p = 0.002). 10 (37.0%) patients treated with complement inhibitors developed breakthrough hemolysis (BTH). Patients treated with complement inhibitors (n = 27) exhibited less severe hemolysis than treatment-naïve patients (n = 104; p = 0.003).

CONCLUSIONS

Omicron infection exacerbates hemolytic attacks in patients with PNH. Vaccination helps mitigate the severity of Omicron infection, and using complement inhibitors reduces hemolysis exacerbation.

Progress in the Management of Pregnancy with Paroxysmal Nocturnal Hemoglobinuria: A Review

Paroxysmal nocturnal hemoglobinuria (PNH) is a rare acquired complement-mediated hemolytic disease characterized by intravascular hemolysis, thrombosis, smooth muscle dystonia, and so on. Thrombosis is the principal cause of death in PNH patients. During the perinatal period, pregnant PNH patients have increased morbidity and mortality with a heightened risk of complications, including significant preterm birth. The management of pregnancy complicated by PNH is difficult. Therefore, early diagnosis, standardized treatment protocols, and improving perinatal outcomes are crucial. However, there is a lack of consensus on treating patients with PNH during pregnancy. This article reviews 32 studies of pregnancy affected by PNH, focusing on the clinical presentation, diagnosis, and treatment strategies of PNH, to provide guidance for obstetricians on how to handle pregnant patients with PNH, and to offer academic support for the management of PNH patients. We found that Eculizumab has become the primary choice for treating PNH, effectively controlling intravascular hemolysis and reducing the frequency of blood transfusions necessary to stabilize the condition, with no severe threat to the safety of the mother and fetus.

Predictors for improvement in patient-reported outcomes: post hoc analysis of a phase 3 randomized, open-label study of eculizumab and ravulizumab in complement inhibitor-naive patients with paroxysmal nocturnal hemoglobinuria

Paroxysmal nocturnal hemoglobinuria (PNH) is characterized by uncontrolled terminal complement activation leading to intravascular hemolysis (IVH), thrombosis, and impairments in quality of life (QoL). The aim of this study was to identify the clinical drivers of improvement in patient-reported outcomes (PROs) in patients with PNH receiving the complement component 5 (C5) inhibitors eculizumab and ravulizumab.This post hoc analysis assessed clinical outcomes and PROs from 246 complement inhibitor-naive patients with PNH enrolled in a phase 3 randomized non-inferiority study that compared the C5 inhibitors ravulizumab and eculizumab (study 301; NCT02946463). The variables of interest were lactate dehydrogenase (LDH) levels, a surrogate measure of IVH, and hemoglobin (Hb) levels. PROs were collected using Functional Assessment of Chronic Illness Therapy-Fatigue (FACIT-F) and European Organisation for Research and Treatment of Cancer, Quality of Life Questionnaire-Core 30 (EORTC QLQ-C30) to assess fatigue and QoL, respectively.Improvements in absolute mean LDH levels were significantly associated with improvements in mean FACIT-F score (p = 0.0024) and EORTC QLQ-C30 global health (GH) score (p < 0.0001) from baseline to day 183. Improvements in scores were achieved despite a non-significant increase in Hb levels. To understand the interaction between LDH and Hb, a regression analysis was performed: LDH response with Hb improvements was a significant predictor of improvement in fatigue. The independent effect of improved Hb did not significantly affect FACIT-F or EORTC QLQ-C30 GH scores.These findings suggest that LDH levels are an important determinant of fatigue and QoL outcomes in patients with PNH. CTR: NCT02946463, October 27, 2016.

Candida krusei pneumonia in graft-versus-host disease after allogeneic hematopoietic stem cell transplant for paroxysmal nocturnal hemoglobinuria: a case report

Introduction and importance

Paroxysmal nocturnal hemoglobinuria (PNH) is a rare disorder caused by a somatic mutation of PIGA (phosphatidylinositol glycan anchor biosynthesis, class A) gene that leads to the destruction of blood cells. Allogeneic haematopoietic stem cell transplant (HSCT) is a treatment option for PHN, but it can cause graft-versus-host disease (GVHD). Long-term immunosuppression as a treatment of GVHD increases the risk for invasive fungal infections such as Candida krusei pneumonia.

Case presentation

We present the case of a 22-year-old male with C. krusei pneumonia in a known case of chronic GVHD following HSCT for PNH undergoing long-term immunosuppressive therapy. The patient presented with progressive shortness of breath, productive cough, palpitations, and difficulty swallowing. On examination, he had skin rashes and oral lesions, along with signs of severe malnutrition. Diagnosis was made on the basis of radiological imaging and fungal culture.

Discussion

The combination of PNH, GVHD, and HSCT created an immunocompromised state, making the patient susceptible to opportunistic infections, including fungal pneumonia. Early recognition of this condition is challenging due to its non-specific symptoms and potential overlap with other post-transplant complications. Timely diagnosis and appropriate treatment, including antifungal therapy and immunosuppression management, are crucial for optimising patient outcomes.

Conclusion

This case highlights the importance of early recognition and timely treatment of fungal infections in patients with severe conditions such as GVHD following HSCT for PNH. Timely treatment with appropriate antifungals is necessary for optimal outcomes. Additionally, more research with long-term follow-up and monitoring is necessary to address the necessary knowledge gaps in this field.

Cost-effectiveness of ravulizumab compared with eculizumab for the treatment of paroxysmal nocturnal hemoglobinuria in the Netherlands

OBJECTIVES

The aim of this study was to evaluate the cost-effectiveness of ravulizumab compared with eculizumab for the treatment of adult patients with paroxysmal nocturnal hemoglobinuria (PNH) in the Netherlands.

METHODS

A cost-effectiveness analysis was conducted based on a Markov cohort model simulating the course of patients with PNH with clinical symptom(s) indicative of high disease activity, or who are clinically stable after having been treated with eculizumab for at least the past six months. Costs, quality of life, and the incremental cost-effectiveness ratio (ICER) were estimated over a lifetime horizon from a Dutch societal perspective. Several additional analyses were performed, including a one-way sensitivity analysis, a probabilistic sensitivity analysis, and scenario analysis.

RESULTS

When compared with eculizumab, ravulizumab saves €266,833 and 1.57 quality adjusted life years (QALYs) are gained, resulting in a dominant ICER. Drug costs account for the majority of the total costs in both intervention groups. Cost savings were driven by the difference in total treatment costs of ravulizumab compared with eculizumab caused by the reduced administration frequency, accounting for 98% of the total cost savings. The QALY gain with ravulizumab is largely attributable to the improved quality of life associated with less frequent infusions and BTH events. At a willingness-to-pay threshold of €20,000/QALY, there is a 76.6% probability that ravulizumab would be cost-effective.

CONCLUSIONS

The cost reduction and QALY gain associated with the lower rates of BTH and less frequent administration make ravulizumab a cost-saving and clinically beneficial substitute for eculizumab for adults with PNH in the Netherlands.

Interventions in cerebrovascular emergencies among patients with Paroxysmal nocturnal haemoglobinuria - A word of caution

INTRODUCTION

Paroxysmal nocturnal haemoglobinuria (PNH) is a clonal hematopoietic disorder, where there is deficiency of glycosylphosphatidylinositol (GPI) anchored proteins in the cell membrane, leading to increased complement sensitivity of red blood cells, intravascular hemolysis and vascular inflammation. Arterial and venous strokes in patients with PNH are a rarity posing significant diagnostic and therapeutic challenges. We report our experience with management of PNH patients with cerebrovascular emergencies.

METHODS

We report 2 patients with PNH, one who was previously diagnosed with PNH and had arterial stroke, the other had an index presentation of cerebral venous sinus thrombosis (CVT) and was subsequently diagnosed with PNH. We also present the systematic review of literature reporting similar cases, highlighting the challenges in management.

RESULTS

Both patients presented to our centre with cerebrovascular emergency. The first patient was a diagnosed with PNH, and presented with left hemispheric infarction caused by thrombosis of middle cerebral artery. He was thrombolysed and underwent mechanical thrombectomy, which was unsuccessful in view of repeated re - thrombosis of the vessel. The patient survived with significant disability. The second patient had severe cerebral venous sinus thrombosis with large right hemispheric hemorrhagic venous infarction. She underwent emergency decompressive hemicraniectomy complicated by massive blood loss and disseminated intravascular coagulation. She subsequently had recurrent life threatening intracranial bleed secondary to platelet transfusions, thrombocytopenia, and use of contrast agents. She progressed to develop Budd Chiari syndrome and was initiated on Eculuzimab. She became transfusion independent, however remained in minimally conscious state and succumbed to sepsis.

CONCLUSIONS

Management of arterial and venous strokes is complex in patients with PNH. Invasive procedures and platelet transfusions are to be avoided in acute thrombosis, till robust evidence is available establishing the safety of the same in patients with PNH. Eculuzimab is a promising option, but far from reach for patients in developing countries.

Long-term effectiveness of eculizumab: Data from the International PNH Registry

OBJECTIVES

Data from the International PNH Registry (NCT01374360) were used to estimate the overall survival and first occurrence of thromboembolic events/major adverse vascular events (TEs/MAVEs) for eculizumab-treated patients with paroxysmal nocturnal hemoglobinuria (PNH) compared with a contemporaneous untreated cohort.

METHODS

Patients enrolled in the Registry from March 16, 2007, to February 14, 2022, were included. Treated patients received eculizumab for >35 days; untreated patients did not receive eculizumab at any time. Univariable and multivariable analyses were performed using a Cox proportional hazards regression model comparing eculizumab treatment periods to untreated periods and were adjusted for baseline covariates (e.g., high disease activity [HDA], transfusion dependency, and eculizumab treatment status).

RESULTS

The analysis included 4118 patients. The univariable hazard ratio (HR) (95% CI) for mortality in eculizumab-treated time versus untreated time was 0.51 (0.41-0.64; p < 0.0001). Significant baseline covariates included age, sex, history of bone marrow failure, ≥4 erythrocyte transfusions within 12 months before baseline, and an estimated glomerular filtration rate ≤ 60 mL/min/1.73 m2 (all p < 0.0001). In the adjusted analysis, patients with baseline HDA had the greatest reduction in mortality risk (HR [95% CI], 0.51 [0.36-0.72]). Treated patients had approximately 60% reduction in TE/MAVE risk during treated versus untreated time (HR [95% CI]: TE: 0.40 [0.26-0.62], MAVE: 0.37 [0.26-0.54]; p < 0.0001).

CONCLUSION

Using data from the largest Registry of patients with PNH, with ≥14 years of overall follow-up, we demonstrate that treatment with eculizumab conferred a 49% relative benefit in survival and an approximately 60% reduction in TE/MAVE risk.

Complement and platelets: prothrombotic cell activation requires membrane attack complex-induced release of danger signals

Complement activation in the diseases paroxysmal nocturnal hemoglobinuria (PNH) and atypical hemolytic uremic syndrome (aHUS) results in cytolysis and fatal thrombotic events, which are largely refractory to anticoagulation and/or antiplatelet therapy. Anticomplement therapy, however, efficiently prevents thrombotic events in PNH and aHUS, but the underlying mechanisms remain unresolved. We show that complement-mediated hemolysis in whole blood induces platelet activation similarly to activation by adenosine 5'-diphosphate (ADP). Blockage of C3 or C5 abolished platelet activation. We found that human platelets failed to respond functionally to the anaphylatoxins C3a and C5a. Instead, complement activation did lead to prothrombotic cell activation in the whole blood when membrane attack complex (MAC)-mediated cytolysis occurred. Consequently, we demonstrate that ADP receptor antagonists efficiently inhibited platelet activation, although full complement activation, which causes hemolysis, occurred. By using an established model of mismatched erythrocyte transfusions in rats, we crossvalidated these findings in vivo using the complement inhibitor OmCI and cobra venom factor. Consumptive complement activation in this animal model only led to a thrombotic phenotype when MAC-mediated cytolysis occurred. In conclusion, complement activation only induces substantial prothrombotic cell activation if terminal pathway activation culminates in MAC-mediated release of intracellular ADP. These results explain why anticomplement therapy efficiently prevents thromboembolisms without interfering negatively with hemostasis.

Long-Term Efficacy and Safety of Eculizumab in Patients With Paroxysmal Nocturnal Hemoglobinuria and High Disease Burden: Real-World Data From Korea

BACKGROUND

Paroxysmal nocturnal hemoglobinuria (PNH) is a rare hematologic disorder characterized by uncontrolled terminal complement activation. Eculizumab, a monoclonal antibody C5 inhibitor was introduced in Korea in 2009 and has been the standard treatment option for PNH.

METHODS

This study assessed the long-term efficacy/safety of eculizumab in PNH using real-world data from the Korean Health Insurance Review and Assessment Service. Eighty patients who initiated eculizumab from 2009-2020 were enrolled.

RESULTS

At eculizumab initiation, the median age was 51.5 years, lactate dehydrogenase (LDH) 6.8 × upper limit of normal, and granulocyte clone size 93.0%. All patients had at least one PNH-related complication before eculizumab initiation, including renal failure (n = 36), smooth muscle spasm (n = 24), thromboembolism (n = 20), and pulmonary hypertension (n = 15). The median (range) duration of eculizumab treatment was 52.7 (1.0, 127.3) months (338.6 total treated patient-years). Despite high disease activity in the study population before treatment initiation, overall survival was 96.2% and LDH levels were stabilized in most patients during treatment. PNH-related complications at treatment initiation were resolved in 44.4% of patients with renal failure, 95.8% with smooth muscle spasm, 70.0% with thromboembolism, and 26.7% with pulmonary hypertension. Extravascular hemolysis occurred in 28.8% of patients (n = 23; 0.09 per patient-year) and breakthrough hemolysis in 18.8% (n = 15; 0.06 per patient-year). No treatment discontinuation cases related to eculizumab were observed.

CONCLUSION

These data provided evidence for the long-term efficacy and safety of eculizumab in Korean PNH patients with high disease burdens.

Analysis of Costs per Responder in US Adults with Paroxysmal Nocturnal Hemoglobinuria with a Suboptimal Response to Prior Eculizumab Treatment

European Society for Blood and Marrow Transplantation (EBMT) hematologic response categories comprehensively assess complement inhibitor responses in patients with paroxysmal nocturnal hemoglobinuria (PNH). Using data from the 16-week randomized controlled period of the phase 3 PEGASUS trial (N = 80), we estimated the treatment cost per responder by the EBMT response category for pegcetacoplan and eculizumab in adults with PNH and a suboptimal response to eculizumab. Average drug costs per responder, number needed to treat, and incremental drug costs per responder were estimated using dosages administered during the trial (base case). A US payer perspective (2020 US dollars) was used. Scenario analyses were conducted for various costs, dosages, treatment durations, patient populations, and settings. In total, 30 of 41 (73%) who switched to pegcetacoplan and 2 of 39 (5%) patients who continued eculizumab had a good, major, or complete response (good-to-complete responders) at Week 16. Average weekly drug costs per good-to-complete responder were USD 15,923 with pegcetacoplan and USD 216,100 with eculizumab; average weekly drug costs per patient were USD 11,651 and USD 11,082, respectively. Average drug costs per good-to-complete responder with pegcetacoplan were similar across complement inhibitor-naïve populations and were consistently lower than with eculizumab. Switching from eculizumab to pegcetacoplan allowed more patients with a suboptimal response to attain a good-to-complete response at lower costs. These results apply to patients with a suboptimal response to prior eculizumab treatment only.

Non-capsulated Neisseria meningitidis sepsis in a paroxysmal nocturnal hemoglobinuria patient treated with ravulizumab: case report and review of the literature

Paroxysmal nocturnal haemoglobinuria (PNH) is a rare acquired haematopoietic stem cell disease characterized by complement-mediated intravascular hemolysis, thrombosis, and bone marrow failure. Eculizumab and ravulizumab are anti-C5 monoclonal antibodies that reduce hemolysis, anaemia and thrombotic risk, but are associated with increased risk of infection with encapsulated bacteria, including Neisseria meningitidis. We report a case of life-threatening infection by non-groupable Neisseria meningitidis in a young PNH patient treated with ravulizumab. Despite prompt admission to the intensive care unit, microbe isolation was delayed due to the negativity of capsular antigens, and the patient required intubation, dialysis, and transfusion support for pancytopenia. Notably, PNH disease activity remained controlled and no additional anti-C5 doses were administered. Increasing awareness regarding septic risk in PNH patients on complement inhibitors despite vaccinations is pivotal. A warning about serotypes generally not pathogenetic and not covered by vaccination, such as non-capsulated forms, is emerging.

Cerebral venous thrombosis in patients with autoimmune disease, hematonosis or coronavirus disease 2019: Many familiar faces and some strangers

BACKGROUND

Cerebral venous thrombosis, a rare stroke, is characterized by neurological dysfunction caused by bleeding and/or infarction resulting from venous sinus thrombosis, the so-called venous stroke. Current guidelines recommend anticoagulants as first-line therapy in the treatment of venous stroke. With complicated causes of cerebral venous thrombosis, treatment is difficult, especially when combined with autoimmune diseases, blood diseases, and even COVID-19.

AIMS

This review summarizes the pathophysiological mechanisms, epidemiology, diagnosis, treatment, and clinical prognosis of cerebral venous thrombosis combined with autoimmune diseases, blood diseases, or infectious diseases such as COVID-19.

CONCLUSION

A systematic understanding of particular risk factors that should not be neglected when unconventional cerebral venous thrombosis occurs and for a scientific understanding of pathophysiological mechanisms, clinical diagnosis, and treatment, thus contributing to knowledge on special types of venous stroke.

Early Mortality in Paroxysmal Nocturnal Hemoglobinuria

OBJECTIVES

 The elevated mortality risk among patients with paroxysmal nocturnal hemoglobinuria (PNH) has been suggested to derive from a high risk of thromboembolism (TE); however, the risks of coexisting cardiovascular risk factors are not well described. We studied mortality associated with PNH taking comorbidity and treatment into account.

METHODS

Patients with PNH (n=115) were identified in the 1977-2016 Danish National Patient Register (DNPR). For each patient with PNH, we identified 50 age- and sex-matched general population comparators. Using the Kaplan-Meier estimator and Cox regression, we compared the overall survival of patients with comparators. Cumulative incidences were used to analyze the effects of comorbidity and the causes of death.

RESULTS

One-year survival among patients and comparators was 92.2% and 99.4%, and after 10 years, it was 68.4% and 85.8%, respectively. Early mortality was associated with older age, higher levels of comorbidity, and solid malignancies prior to PNH diagnosis. The leading causes of death were infections and associated hematological diseases. Patients with early mortality were less likely to have received treatment with eculizumab and/or warfarin. Cardiovascular risk factors were evenly distributed between patients and comparators at diagnosis.

CONCLUSION

We conclude that early mortality in PNH is associated with older age, cardiovascular comorbidity, and hematological malignancies.

Real-world safety profile of eculizumab in patients with paroxysmal nocturnal hemoglobinuria, atypical hemolytic uremic syndrome, or generalized myasthenia gravis: an integrated analysis of post-marketing surveillance in Japan

Eculizumab is a C5 inhibitor approved for the treatment of paroxysmal nocturnal hemoglobinuria (PNH), atypical hemolytic uremic syndrome (aHUS), and anti-acetylcholine receptor antibody-positive generalized myasthenia gravis (AChR + gMG) in Japan. We report integrated safety data from post-marketing surveillance in these three indications, focusing on commonly occurring adverse events (AEs) and infection-related AEs. Of 1219 patients registered, 1055 (PNH: 780; aHUS: 192; AChR + gMG: 83) had available safety data. Total eculizumab exposure was 3977.361 patient-years. AEs were reported in 74.03% of patients. AEs with an incidence of  ≥ 1.0 per 100 patient-years included hemolysis, headache, nasopharyngitis, renal impairment, anemia, pneumonia, upper respiratory tract inflammation, influenza, condition aggravated, and infection. The incidence of infection-related AEs was 21.30 per 100 patient-years, the most frequent types (≥ 1.0 per 100 patient-years) being nasopharyngitis, pneumonia, influenza, and infection. Meningococcal infections were reported in four patients (0.10 per 100 patient-years). Two patients died from meningococcal sepsis, with a mortality rate of 0.05 per 100 patient-years. This is the largest safety dataset on eculizumab in Japan derived from more than 10 years of clinical experience. No new safety signals were observed and the safety profile of eculizumab was consistent with that in previous clinical trials and international real-world safety analyses.

Complement in immune thrombocytopenia (ITP): The role of complement in refractory ITP

Immune thrombocytopenia (ITP) is a disorder characterized by low platelets due to increased clearance and decreased platelet production. While ITP has been characterized as an acquired disorder of the adaptive immune system, the resulting platelet autoantibodies provide ancillary links to the innate immune system via antibody interaction with the complement system. Most autoantibodies in patients with ITP are of the IgG1 subclass, which can be potent activators of the classical complement pathway. Antibody-coated platelets can initiate complement activation via the classical pathway leading to both direct platelet destruction and enhanced clearance of C3b-coated platelets by complement receptors. Similar autoantibody interactions with bone marrow megakaryocytes can also result in complement injury and ineffective thrombopoiesis. The development of novel therapeutic complement inhibitors has revived interest in the role of complement in autoantibody-mediated disorders, such as ITP. A recent early-phase clinical trial of a classical complement pathway inhibitor has demonstrated efficacy in a subset of ITP patients refractory to conventional immune modulation. In this review, we will analyse the role of complement in refractory ITP.

Interim analysis of post-marketing surveillance of ravulizumab for paroxysmal nocturnal hemoglobinuria in Japan

Ravulizumab is a long-acting C5 inhibitor available for treating paroxysmal nocturnal hemoglobinuria (PNH). Post-marketing surveillance (PMS) was implemented following its approval in September 2019 in Japan. We report safety data obtained through to December 2021 for 218 patients and effectiveness data for 194 patients (182 switched from eculizumab and 12 complement inhibitor-naïve). Over a median follow-up of 74.4 weeks, 193 adverse events (AEs) were reported in 66/218 patients (30.3%; incidence 72.73/100 patient-years). The two most frequent AEs were anemia and pyrexia (each 3.01/100 patient-years). The incidence of serious AEs was 36.93/100 patient-years. In patients who switched from eculizumab, lactate dehydrogenase (LDH) and hemoglobin (Hb) levels were maintained over 26 weeks of ravulizumab treatment. In complement inhibitor-naïve patients, LDH decreased significantly and Hb increased significantly over 26 weeks of ravulizumab treatment. These data for Japanese patients with PNH who were naïve to complement inhibitors and patients who switched from eculizumab show that the safety and effectiveness of ravulizumab are consistent with the published clinical trial data. However, transfusion independence was less likely in patients with bone marrow failure. Further follow-up data from this PMS will help to elucidate the long-term clinical safety and effectiveness of ravulizumab for treating PNH.

Characteristics of paroxysmal nocturnal hemoglobinuria patients in Brazil: A retrospective administrative claims database analysis of PNH patients in Brazilian public healthcare system

INTRODUCTION

Few studies have reported the profile of patients with paroxysmal nocturnal hemoglobinuria (PNH) and their care in the Brazilian health system.

OBJECTIVE

To describe clinical and epidemiological characteristics of patients with PNH in the Brazilian public health system including procedures performed, associated comorbidities and visits to health care professionals.

METHODS

In a real-world observational, retrospective, population-based cohort study, anonymized secondary data provided by the Department of Informatics of the Brazilian Unified Health System (DATASUS) were analyzed. Patients were considered eligible if they had at least one procedure coded with the ICD-10 code D59.5 from January 1, 2008 to December 30, 2018.

RESULTS

In total, 675 individual PNH patients were identified (52.4% female; prevalence of 1:237,000 people). Around 15.8% of the patients included had myelodysplastic syndrome and about half of the sample had other aplastic anemias and/or other bone marrow failure syndromes. Portal vein thrombosis (I82 ICD code) was reported in 4.3% of patients. Regarding hospitalizations, 263 individual PNH patients had 416 inpatient admissions with the ICD code for PNH (D59.5) on admission. Twelve deaths occurred during the study period, of which two had the PNH ICD code related with the cause of death, while another three deaths were associated with acquired hemolytic anemia (D59.9), unspecified aplastic anemia (D61.9) and acute respiratory failure (J96.0), respectively.

CONCLUSION

Despite its limitations, this statistical analysis of data extracted from DATASUS reasonably describes PNH patients in Brazil and its variations across different regions of the country. Comorbidities frequently associated with PNH such as portal vein thrombosis were not as common in our study, but it is assumed that several thrombotic events at specific sites were coded under the broader I82 ICD code. The frequency of visits to different health professionals, including hematologists, increased after the diagnosis of PNH. Among hospitalized PNH patients, the mortality rate was 4.5%.

Swiss Survey on current practices and opinions on clinical constellations triggering the search for PNH clones

This national survey investigated the current practice in Switzerland by collecting participants' opinions on paroxysmal nocturnal hemoglobinuria (PNH) clone assessment and clinical practice.

Aim

This study aimed to investigate clinical indications prompting PNH clones' assessment and physician's accessibility of a flow cytometry facility, and also to understand clinical attitudes on the follow-up (FU) of patients with PNH clones.

Methods

The survey includes 16 multiple-choice questions related to PNH and targets physicians with a definite level of experience in the topic using two screener questions. Opinion on clinical management was collected using hypothetical clinical situations. Each participant had the option of being contacted to further discuss the survey results. This was an online survey, and 264 physicians were contacted through email once a week for 5 weeks from September 2020.

Results

In total, 64 physicians (24.2%) from 23 institutions participated (81.3% hematologists and 67.2% from university hospitals). All had access to flow cytometry for PNH clone testing, with 76.6% having access within their own institution. The main reasons to assess for PNH clones were unexplained thrombosis and/or hemolysis, and/or aplastic anemia (AA). Patients in FU for PNH clones were more likely to be aplastic anemia (AA) and symptomatic PNH. In total, 61% of the participants investigated PNH clones repetitively during FU in AA/myelodysplastic syndromes patients, even when there was no PNH clone found at diagnosis, and 75% of the participants tested at least once a year during FU. Opinions related to clinical management were scattered.

Conclusion

The need to adhere to guidelines for the assessment, interpretation, and reporting of PNH clones emerges as the most important finding, as well as consensus for the management of less well-defined clinical situations. Even though there are several international guidelines, clear information addressing specific topics such as the type of anticoagulant to use and its duration, as well as the indication for treatment with complement inhibitors in some borderline situations are needed. The analysis and the discussion of this survey provide the basis for understanding the unmet needs of PNH clone assessment and clinical practice in Switzerland.

Gata1s mutant mice display persistent defects in the erythroid lineage

GATA1 mutations that result in loss of the N-terminal 83 amino acids are a feature of myeloid leukemia in children with Down syndrome, rare familial cases of dyserythropoietic anemia, and a subset of cases of Diamond-Blackfan anemia. The Gata1s mouse model, which expresses only the short GATA1 isoform that begins at methionine 84, has been shown to have a defect in hematopoiesis, especially impaired erythropoiesis with expanded megakaryopoiesis, during gestation. However, these mice reportedly did not show any postnatal phenotype. Here, we demonstrate that Gata1s mutant mice display macrocytic anemia and features of aberrant megakaryopoiesis throughout life, culminating in profound splenomegaly and bone marrow fibrosis. These data support the use of this animal model for studies of GATA1 deficiencies.

Clinically important change for the FACIT-Fatigue scale in paroxysmal nocturnal hemoglobinuria: a derivation from international PNH registry patient data

BACKGROUND

Fatigue is the most common symptom associated with paroxysmal nocturnal hemoglobinuria (PNH). The objective of this analysis was to estimate values that would suggest a clinically important change (CIC) for the functional assessment of chronic illness therapy-fatigue scale (FACIT-Fatigue) in patients with PNH.

METHODS

Adults with PNH who initiated eculizumab within 28 days of enrollment in the International PNH Registry as of January 2021 with baseline FACIT-Fatigue scores were included in the analysis. Distribution-based estimates of likely difference were calculated using 0.5 × SD and SEM. Anchor-based estimates of CIC considered the European Organization for Research and Treatment of Cancer (EORTC) global health status/quality of life summary score and the EORTC Fatigue Scale score. Changes in anchors and high disease activity (HDA) shift from start of eculizumab treatment to each follow-up visit were then assessed by FACIT-Fatigue score change (≤ 1 CIC, no change, or ≥ 1 CIC).

RESULTS

At baseline, 93% of 423 patients had fatigue documented in their medical history. The distribution-based estimates for FACIT-Fatigue were 6.5 using 0.5 × SD and 4.6 using SEM; internal consistency was high (α = 0.87). For anchor-based estimates, the FACIT-Fatigue CIC ranged from 2.5 to 15.5, and generally supported 5 points as a reasonable lower end of the value for meaningful individual change. The percentage of patients who changed from having HDA at baseline to no HDA at eculizumab-treated follow-up visits increased over time.

CONCLUSION

These results support the use of 5 points as the CIC for FACIT-Fatigue in patients with PNH, which is within range of the CICs reported in other diseases (3-5 points).

Eculizumab for paroxysmal nocturnal haemoglobinuria: catastrophic health expenditure in Nepalese patients

Paroxysmal nocturnal hemoglobinuria (PNH) results from a mutation in the phosphatidylinositol glycan class-A gene which causes uncontrolled complement activation with resultant intravascular hemolysis and its sequelae. Eculizumab is a terminal complement inhibitor that blocks this complement activation and has revolutionized the treatment of PNH but comes with an enormous price which can have catastrophic health expenditure in low-middle income countries (LMIC) like Nepal. Here, we discuss the potential way forwards in the treatment of PNH in Nepal and other LMICs.

Crovalimab treatment in patients with paroxysmal nocturnal haemoglobinuria: Long-term results from the phase I/II COMPOSER trial

OBJECTIVES

This study reports long-term outcomes from the open-label extension (OLE) period of the Phase I/II COMPOSER trial (NCT03157635) that evaluated crovalimab in patients with paroxysmal nocturnal haemoglobinuria, who were treatment-naive or switched from eculizumab at enrolment.

METHODS

COMPOSER consists of four sequential parts followed by the OLE. The primary OLE objective was to assess long-term crovalimab safety, with a secondary objective to assess crovalimab pharmacokinetics and pharmacodynamics. Exploratory efficacy endpoints included change in lactate dehydrogenase (LDH), transfusion avoidance, haemoglobin stabilisation and breakthrough haemolysis (BTH).

RESULTS

A total 43 of 44 patients entered the OLE after completing the primary treatment period. Overall, 14 of 44 (32%) experienced treatment-related adverse events. Steady state exposure levels of crovalimab and terminal complement inhibition were maintained over the OLE. During the OLE, mean normalised LDH was generally maintained at ≤1.5× upper limit of normal, transfusion avoidance was achieved in 83%-92% of patients and haemoglobin stabilisation was reached in 79%-88% of patients across each 24-week interval. Five BTH events occurred with none leading to withdrawal.

CONCLUSIONS

Over a 3-year median treatment duration, crovalimab was well tolerated and sustained C5 inhibition was achieved. Intravascular haemolysis control, haemoglobin stabilisation and transfusion avoidance were maintained, signifying long-term crovalimab efficacy.